This invention relates to hollow core load-bearing base panels such as may be incorporated in airfreight containers, load-bearing pallets, vehicle cargo platforms and the like. The invention is herein illustratively described by reference to the presently preferred embodiment thereof; however, it will be recognized that certain modifications and changes therein with respect to details may be made without departing from the essential features involved.
While the attribute of high strength with low tare weight is important in cargo carrier containers generally for truck rail and shipboard applications, it is obviously even more critical in the case of air transport carriers wherein weight savings can save a shipper large sums over a period of time. The base or floor structure of such containers is usually the most vulnerable to overload damage and usually, therefore, the part of the container where weight penalties are paid for the sake of added strength. For instance, the wheels of a loaded forklift truck can impose heavy force concentrations on the top sheet of a hollow core floor or base panel and, if not adequately resisted by underlying support, can cause panel damage. Likewise, a hump or other localized projection on an underlying floor can place undue upwardly directed deflection load on the bottom sheet of the base panel. Simply increasing the thickness of the top sheet and/or increasing the number of underlying panel ribs, or providing cross ribs, interconnecting the top and bottom sheets has not been a satisfactory solution to the problem because of the large addition of weight imposed without commensurate increase in strength.
A broad object of the present invention, therefore, is to substantially strengthen the base panel of a freight container with minimum increase in weight. A related object is to achieve this result with minimum increase in cost of construction of the base panel and without necessity of complicating the same nor of departing from typical or special fabrication procedures used in making up the base structure.
A related object hereof is to provide a versatile supplemental support system for the top and bottom sheets of hollow core container base panels which can be made highly specific to particular load distribution requirements of the container base for each individual application. As a consequence, the invention makes frugally efficient use of any weight increasing elements added to strengthen the base panel. When employing the invention, subassemblies for one basic panel structure can be stocked by a manufacturer and can be efficiently adapted on final assembly to suit the specific load distribution design requirements of each unit or production run of units.
A specific object hereof is to achieve those and related objectives using readily available and relatively inexpensive materials that can be applied and fitted with the simpliest of tools and with a minimum level of skill.